Search PubMed⌕ Search

Biomedical subjects

M Takeda

Publications and source records attributed to M Takeda.

At least 703 records · Page 39Linked to original sources
PubMed1991

Assembly, disassembly, and exchange of glial fibrillary acidic protein.

The kinetics and dynamics of glial fibrillary acidic protein (GFAP) assembly was explored by a fluorescence energy transfer assay method. Purified GFAP was stoichiometrically labeled at a single cysteine residue with fluorescein-maleimide. Soluble labeled GFAP in a low ionic strength buffer was assembled into 10 nm filaments by rapidly increasing the ionic strength, and the kinetics of GFAP assembly was monitored by the reduction in fluorescence due to self-quenching of fluorescein. The extent of fluorescence quench correlated with both the formation of 10 nm filament morphology and the amount of protein pelleted at 12,000g. The assembly of GFAP is critically dependent upon both protein and magnesium ion concentration, and at the critical concentration for GFAP assembly is approximately 40 micrograms/ml. Disassembly of GFAP filaments was also observed as a relief of fluorescence quenching after dilution of labeled GFAP filaments. When labeled GFAP filaments were mixed with an excess of unlabeled filaments, a rapid increase of fluorescence was observed, which is due to an exchange of subunits between labeled and unlabeled GFAP filaments. These results indicate that GFAP filaments are dynamic structures and that a small pool of kinetically active unassembled GFAP subunits are in a dynamic equilibrium with assembled GFAP filaments. The ability of GFAP to assemble, disassemble, and undergo subunit exchange has important implications for the organization and dynamics of astroglia cell cytoskeleton during development and in response to injury.

Animals↗
PubMed1991

Alpha-1 antichymotrypsin is increased in human alveolar macrophages by phorbol myristate acetate or lipopolysaccharide and released from these activated macrophages by glucocorticoid.

Alveolar macrophages were obtained from 23 patients and the effects of phorbol myristate acetate (PMA), lipopolysaccharide (LPS), and dexamethasone (DEX) on the proportion of cells with intracellular alpha-1 antichymotrypsin (ACT), and concentrations of ACT in the culture medium were studied in vitro. The alveolar macrophages were obtained by bronchoalveolar lavage at autopsy or from resected lungs at operation and were cultured in suspension for 3 days in medium containing PMA, LPS, DEX, PMA+DEX, or LPS+DEX. Both PMA and LPS significantly increased the percentage of macrophages with intracellular ACT. Dexamethasone did not increase the number of ACT-positive cells and significantly suppressed the increase induced by PMA or LPS, releasing ACT into the culture medium. The release of ACT from macrophages may contribute to the anti-inflammatory effects of corticoids.

Adult↗
PubMed1991

Immunohistochemical study of microtubule-associated protein 2 and ubiquitin in chronically aluminum-intoxicated rabbit brain.

Experimental neurofibrillary change was produced in rabbit brain by daily subcutaneous aluminum tartrate injection for 40 days. The production of experimental neurofibrillary changes was confirmed by immunostaining with antibodies against neurofilament triplet proteins and the brain tissue was studied immunohistochemically with antibodies against microtubule-associated protein (MAP) 2 and ubiquitin. The hippocampal neurons of the chronically aluminum-intoxicated rabbit brain showed diminished staining of dendrites by anti-MAP2 antibody. The length of anti-MAP2-positive dendrites in hippocampus was significantly shorter than that of the control brain. In the cortex somata of a subset of pyramidal neurons were intensively stained by anti-MAP2 antibody, while the MAP2 immunoreactivity of distal dendrites was diminished. The immunostaining by anti-ubiquitin antibody revealed the positive staining of the neurons bearing experimental neurofibrillary changes in the lower brain stem nuclei. It is speculated that MAP2 dislocation and ubiquitination are accompanying phenomena of the production of experimental neurofibrillary changes in chronically aluminum-intoxicated rabbit brains.

Aluminum↗
PubMed1991

Basal cells in the mouse olfactory epithelium after axotomy: immunohistochemical and electron-microscopic studies.

The olfactory epithelium of mice after axotomy was investigated to clarify the stem cells of olfactory cells by double immunostaining using antikeratin (MA903) and anti-bromodeoxyuridine (BrdU) antibodies and by conventional electron microscopy. When a single dose of BrdU was given to mice 9 days after axotomy, immunostaining for BrdU was found in the globose basal cells which were negative for MA903, but not in the basal cells proper which were positive for MA903. The BrdU-immunoreactive cells increased 3- to 6-fold over the number of these cells in the controls, indicating active cell proliferation. At other postoperative days (4 and 14 days), fewer BrdU-immunoreactive cells were found. Furthermore, three pulses of BrdU resulted in numerous BrdU-immunolabelings in the globose basal cells and a few in the basal cells proper. There was no detectable difference in the number of labeled basal cells proper in operated and unoperated mice. In the electron micrographs 9 days after axotomy, the basal cells proper, flat-shaped in unoperated mice, appeared cylindrical or pyramidal in shape and the globose basal cells often lay between the basal cells proper. In unoperated controls, the globose basal cells were located above the flat-shaped basal cells proper. The results suggest that the stem cells of the olfactory cells are globose basal cells and not basal cells proper, and that the shape of basal cells proper changes in relation to the active proliferation of stem cells.

Animals↗
PubMed1991

Organochlorine chemicals in skin lipids as an index of their accumulation in the human body.

Application of a noninvasive method of analyzing skin lipids was considered as a means of monitoring human exposure to organochlorine pesticides. Skin lipids were collected by wiping the face with cotton and purified by gel permeation chromatography and treatment with H2SO4. Organochlorine chemicals were determined by electron capture gas chromatography with a fused silica capillary column. p,p'-DDE, beta-HCH and chemicals related to chlordane were detected in the skin lipids. Residue levels of p,p'-DDE, beta-HCH and oxychlordane in the skin lipids correlated with those in the adipose tissue; correlation coefficients for p,p'-DDE, beta-HCH and oxychlordane were 0.93, 0.92, and 0.68, respectively. The correlation between skin lipids and adipose tissue for trans-nonachlor was poor (gamma = 0.46). The component pattern of chlordanes in skin lipids was similar to that of technical chlordane. The results suggested that chemicals in the skin lipids reflected both their accumulation in the body burden and dermal exposure. Skin lipids collected during 1986 to 1988 in Japan were determined for p,p'-DDE, beta-HCH and the chlordanes. Residue levels of p,p'-DDE and beta-HCH in the aged were high compared with those in the young (gamma = 0.31-0.45). Chlordanes were detected from inhabitants in the southern area of Japan where chlordane had been used for termite control.

Female↗
PubMed1991

2',5' Oligoadenylate synthetase activity in peripheral blood mononuclear cells and serum during interferon treatment of chronic non-A, non-B hepatitis.

The 2'-5' oligoadenylate synthetase (2-5 AS) activity of peripheral blood mononuclear cells and serum was measured in 23 patients with chronic non-A, non-B hepatitis during interferon therapy, 16 of whom were found to have antibody to hepatitis C virus (anti-HCV). Patients received a daily dose of either 1 million, 3 million or 6 million units of human interferon-alpha or -beta for 4 to 6 weeks. Before treatment, the 2-5 AS activity was not significantly different from that in normal control subjects or patients with chronic hepatitis B. However, during treatment the 2-5 AS activity increased 2- to 41-fold from the initial level. Alanine aminotransferase (ALT) levels normalized promptly after the start of treatment in 15 (65.2%) of the 23 patients, but remained elevated in the remaining 8 (34.8%). Six (40%) of the 15 patients showed consistently normal ALT levels for 6 to 30 months after the end of treatment. There was no significant difference between the responders and non-responders in the pattern of change of 2-5 AS activity, but pretreatment activity levels in peripheral blood mononuclear cells were significantly higher (P less than 0.001) in the patients whose ALT levels did not normalize during treatment. The frequency of patients with a positive anti-HCV was significantly higher (P less than 0.05) in the group in which ALT levels normalized. Therefore, these findings suggest that the pretreatment 2-5 AS activity and the detection of anti-HCV may be useful parameters for predicting the response to interferon therapy.

2',5'-Oligoadenylate Synthetase↗
PubMed1991

Detection of 2',5' oligoadenylate synthetase activity in acute viral hepatitis with special reference to histologic features in the acute stage.

We measured the sequential changes in 2',5' oligoadenylate synthetase activity in 21 patients with acute viral hepatitis (5 with type A, 6 with type B, and 10 with type non-A, non-B hepatitis) by radioimmunoassay. Liver biopsies were performed during the acute phase in all patients. Among patients with acute hepatitis A and B, the 2',5' oligoadenylate synthetase levels were transiently elevated at the time of the peak alanine aminotransferase level in the patients in whom a liver biopsy showed acute hepatitis or non-specific reactive hepatitis. Of 10 patients with acute non-A, non-B hepatitis, 4 showed a similar 2',5' oligoadenylate synthetase activity pattern and liver histology to those observed in acute hepatitis A and B. In the remaining 6, the 2',5' oligoadenylate synthetase levels remained elevated for 3.5 to 6 months while the alanine aminotransferase was elevated. Liver biopsy in these patients showed chronic hepatitis. Persistent detection of raised 2',5' oligoadenylate synthetase activity levels during the acute stage of non-A, non-B hepatitis may thus be an indicator of progression of the disease.

2',5'-Oligoadenylate Synthetase↗
PubMed1991

Reversible effects of sodium butyrate on the differentiation of F9 embryonal carcinoma cells.

We have studied effects of sodium butyrate on embryonal carcinoma F9 cell differentiation. In the presence of sodium butyrate, F9 cells underwent rapid and drastic morphological changes and expressed marked increases in mRNA levels of various differentiation markers. When sodium butyrate was removed from the cultures, all the examined phenotypes of F9 cell differentiation rapidly reverted to the characteristics of undifferentiated stem cells. However, under the same conditions, when cycloheximide or actinomycin D was added to the cultures, such phenotypic reversion was not observed, but high mRNA levels of the differentiation markers as well as altered cell morphology were retained. These results indicated that the effects of sodium butyrate on induction of teratocarcinoma cell differentiation were reversible and that de novo syntheses of some mRNA(s) and protein(s) were necessary for the reversion of differentiated cells to stem cells.

Animals↗
PubMed1991

Usefulness of 198Au grain implants in the treatment of oral and oropharyngeal cancer.

A series of 177 patients with squamous cell carcinoma of the oral cavity and oropharynx were treated with 198Au grain (gold grain) implants. Sites of the lesion included the tongue, mouth floor, buccal mucosa and oropharynx, especially the soft palate and faucial arch. Three-fourths of the patients were treated in combination with prior external beam irradiation. A permanent implant dose (total decay) of 80-90 Gy was given in the form of gold grains alone and in combination with an external dose of no more than 30 Gy, and 60-70 Gy, total decay, was given after an external dose greater than 30 Gy. The 2-year recurrence-free rate was 86.2% in the case of T1N0, 72.6% in T2N0 and 72.2% in T3N0. The difference in the results of implant therapy alone and combined therapy was not significant. Late complications were minimal after grain implantation alone, and when used in combination, less than 70 mCi of grain activity after a 40 Gy external dose did not seem to be a serious hazard with respect to bone damage except in the case of cancer of the mouth floor. Gold grain implants were useful and easily applied under local anesthesia to early or superficial lesions at sites where a rigid linear source could not be used. Exposure of the radiology staff was only 5-10 mrad in the case of the usual 10-15 (50-75 mCi) implant grains.

Brachytherapy↗
PubMed1991

Synthesis of halogen-substituted 1,5-benzothiazepine derivatives and their vasodilating and hypotensive activities.

In an attempt to improve the effectiveness and duration of the action of diltiazem (1), a 1,5-benzothiazepine calcium channel blocker, its derivatives (2) with halogen substituents on the fused benzene ring were synthesized. These compounds were evaluated for their effects on vertebral and coronary blood flows and antihypertensive activity. The structure-activity relationships are discussed. The 8-chloro derivative ((+)-2b), the most potent compound in this series, was selected for clinical evaluation as a cerebral vasodilating and antihypertensive agent.

Animals↗
PubMed1991

Characterization of myosin heavy and light chains in cultured mesangial cells.

Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that postconfluent mesangial cells in primary culture expressed three myosin heavy chains (MHCs), 204 kD, 200 kD and 196 kD, in a manner similar to that of smooth muscle cells. The MHCs of 204 kD and 200 kD in mesangial cells reacted positively with antibodies raised against bovine aorta smooth muscle myosin while the 196 kD MHC reacted positively with antibodies against platelet myosin. Moreover, the combined content of the MHCs in cultured mesangial cells was remarkably similar in amount to that in cultured aortic smooth muscle cells. After three passages, cultured mesangial cells expressed only the 196 kD MHC as has been reported for cultured smooth muscle cells. Two phosphorylated proteins were found in the immunoprecipitate after incubation of the cell extract with antibodies against platelet myosin: a MHC of approximately 200 kD and myosin light chain (MLC) of 20 kD. The level of MLC phosphorylation was quantitated by scanning densitometry of autoradiograms. Arginine vasopressin (AVP) at 100 nM induced MLC phosphorylation with a maximum effect at 10 minutes. AVP enhanced MLC phosphorylation in a dose dependent manner: maximum response was observed with 100 nM and half maximum, at 3.5 nM. Similarly, angiotensin II (100 nM), endothelin-1 (10 nM) and the calcium ionophore, A23187 (1 microM), significantly enhanced MLC phosphorylation. Thus, although the expression of MHC was altered in quality after mesangial cells were placed in culture, the cells remained rich in myosin content and had an intact regulatory system for contraction which responded to a variety of vasoconstrictive agents.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Foot protein isoforms are expressed at different times during embryonic chick skeletal muscle development.

We have investigated the time course of expression of the alpha and beta triad junctional foot proteins in embryonic chick pectoral muscle. The level of [3H]ryanodine binding in muscle homogenates is low until day E20 of embryonic development, then increases dramatically at the time of hatching reaching adult levels by day N7 posthatch. The alpha and beta foot protein isoforms increase in abundance concomitantly with [3H]ryanodine binding. Using foot protein isoform-specific antibodies, the alpha foot protein is detected in a majority of fibers in day E10 muscle, while the beta isoform is first observed at low levels in a few fibers in day E15 muscle. A high molecular weight polypeptide, distinct from the alpha and beta proteins, is recognized by antifoot protein antibodies. This polypeptide is observed in day E8 muscle and declines in abundance with continued development. It appears to exist as a monomer and does not bind [3H]ryanodine. In contrast, the alpha isoform present in day E10 muscle and the beta isoform in day E20 muscle are oligomeric and bind [3H]ryanodine suggesting that they may exist as functional calcium channels in differentiating muscle. Comparison of the intracellular distributions of the alpha foot protein, f-actin, the heavy chain of myosin and titin in day E10 muscle indicates that the alpha foot protein is expressed during myofibril assembly and Z line formation. The differential expression of the foot protein isoforms in developing muscle, and their continued expression in mature muscle, is consistent with these proteins making different functional contributions. In addition, the expression of the alpha isoform during the time of organization of a differentiated muscle morphology suggests that foot proteins may participate in events involved in muscle differentiation.

Actins↗
PubMed1991

Cytomegalovirus DNA in the sera of patients with cytomegalovirus pneumonia.

We attempted to detect cytomegalovirus DNA (CMV-DNA) in the sera of four leukaemia patients who underwent an allogeneic bone marrow transplant (BMT), in six leukaemia patients who suffered from pneumonia and in 16 healthy subjects, using the polymerase chain reaction (PCR). Three of the four BMT patients subsequently developed CMV pneumonia. In two cases, CMV-DNA was detected in the sera at about the time the pneumonia occurred, and the amount of DNA increased with disease progression. The serum of the third patient became positive for CMV-DNA before he developed pneumonia. The fourth patient did not develop CMV pneumonia, but his urine became persistently positive for CMV-DNA soon after the BMT, whereas the serum was negative. A relationship was found between the occurrence of pneumonia and the serum level of CMV-DNA. CMV-DNA was also detected in three of six pneumonia patients whose anti-CMV IgM antibodies were elevated in the circulation. Sera from the 16 normal subjects were negative for CMV-DNA, regardless of their being seropositive or seronegative for CMV. While it had been previously thought that CMV did not exist in serum, we detected CMV-DNA in serum by PCR in the active disease stage. Our results suggest that PCR would be useful for the early diagnosis of CMV pneumonia and in monitoring its course.

Adolescent↗
PubMed1991

Two cases of peritoneal serous papillary adenocarcinoma.

Two cases of peritoneal papillary carcinoma are reported. The patient in the first case was a 71-year-old woman with symptoms of obstructive ileus. Laparotomy revealed a tumor in the omentum involving the transverse colon, and several small tumors in the peritoneum and pelvic wall. However, no primary site of the tumor was seen in the ovary, pancreas, or gastrointestinal tract. The patient in the second case was a 44-year-old woman with carcinomatous peritonitis. Postmortem examination revealed multiple tumors in the peritoneum, omentum, and pelvic wall. Tumors were also found in the cortex with mild invasion of the underlying parenchyma of the bilateral ovaries, although these lesions were thought to be metastatic. The histologic features of the tumor in both cases were those of tubulopapillary adenocarcinoma containing scattered psammoma bodies. The cells were positive with the PAS-D technique, but negative with alcian blue staining. In both cases, the serum levels of CA-125 were considerably elevated, and the tumor cells showed positivity for CA-125, S-100 protein, cytokeratin and EMA by immunohistochemistry. The present cases were most likely peritoneal serous papillary adenocarcinoma derived from extraovarian peritoneal mesothelium with müllerian potential, being different from the usual type of diffuse malignant mesothelioma.

Adult↗
PubMed1991

Study of cytoskeletal proteins in fibroblasts cultured from familial Alzheimer's disease.

Cytoskeletal proteins of the cultured fibroblasts obtained from Alzheimer's disease patients were studied. Western blotting studies of tubulin, actin, and vimentin showed no difference between Alzheimer and the control fibroblasts. Western blotting studies of vimentin revealed five partial degradation products in 50 K-57 K Da. molecular size region, but no difference in the degradation pattern was noticed between Alzheimer and the control fibroblasts. The size of fodrin molecule, however, was quite different between Alzheimer and the control fibroblasts. Comparing the molecular size of fodrin purified from the bovine brain, it is concluded that fodrin in Alzheimer fibroblasts is not degraded, while significant amount of fodrin in the control fibroblasts is partially degraded resulting in the smaller size of the 160 K and 200 K Da. molecular weight products.

Actins↗
PubMed1991

Mechanisms of NE-induced reduction of Ca current in single smooth muscle cells from guinea pig vas deferens.

Effects of norepinephrine (NE) on voltage-dependent Ca channel current (ICa) were examined applying whole cell patch-clamp technique to single smooth muscle cells freshly isolated from vas deferens of the guinea pig. K currents and contraction of the cell were abolished by Cs and EGTA in the pipette solution, respectively. The peak ICa and Ba current (IBa) elicited by depolarization from -60 mV in a solution containing 2.2 mM Ca or Ba were reduced by 10-60% in voltage- and dose-dependent manners by the application of NE or phenylephrine. This effect was greatly attenuated in the presence of prazosin. The decrease in IBa was always smaller than that in ICa at any potential. Even after simultaneous application of 5 mM caffeine and 10 microM NE to the cells in a Ba-containing solution, the second challenge with NE again reduced IBa in a similar manner. The decrease in IBa by 10 microM NE could not be explained well by a small shift (-5 mV) of the voltage dependence of the steady-state inactivation. The effect of NE on IBa was irreversibly enhanced by 0.1 mM guanosine 5'-O-(3-thiotriphosphate) and almost abolished by 1 mM guanosine 5'-O-(2-thiodiphosphate) added to the pipette solution but appeared not to be affected by the treatment with pertussis toxin. It can be concluded that, under these experimental conditions, the activation of alpha 1-adrenoceptor in vas deferens smooth muscle cells reduces Ca channel activity possibly via a mechanism involving GTP-binding protein in addition to Ca-mediated Ca channel inactivation mechanism.

Animals↗